CN1228059A - solid tire core - Google Patents

Abstract

A rubber tread covers an outside of a tire core having a diameter adapted for fitting on a rim of a wheel, and a peripheral groove is formed in the tire core along an outer peripheral top thereof to be expanded at its inner portion near the rim in an axial direction of a tire. A small load applied in a short time, such as a shock, is cushioned by an elastic bending deformation of that portion of the tire core, which surrounds the peripheral groove, and when a large load is to be born over a long term, the tire core undergoes bending deformation in the tread, accompanied by compressive deformation to provide cushioning. As a result, it is possible to exhibit a soft, elastic force as in a hollow tire without the sacrifice of a load resisting property of the solid tire to adequately cushion a shock from a road surface even when a vehicle in an unloaded condition runs.

Description

solid tire core

The invention relates to a solid tire with a solid elastic element sandwiched between the tire casing and the wheel, a tire core, a casing and a wheel for such a solid tire and to a production thereof process.

It is well known that solid tires generally have the characteristics of not leaking or tying, which can be obtained by installing elastic rubber elements integrally formed with the tire on the rim, or by filling elastic elements in tubeless tires, such as elastic rubber elements. get.

Such solid tires have a higher load-carrying rubber material, such as synthetic rubber, sandwiched inside the tire. Such tires are superior to traditional hollow pneumatic tires in terms of airtightness, and they are especially suitable for heavy-duty transport vehicles. Otherwise, under heavy-duty conditions, it is very difficult to repair tires.

However, a common solid tire is manufactured by installing or filling the tire with elastic elements having specific pressure deformation capabilities. Therefore, the elasticity of this kind of tire cannot be easily adjusted, while for hollow tires, it can be realized by simply adjusting its air pressure. Therefore, when the heavy transport vehicle is lightly loaded or unloaded, conventional solid tires cannot sufficiently cushion the impact from the road surface. Therefore, ordinary tires have more serious problems such as driver fatigue.

In Examined Japanese Patent Publication No. 22641/1986, the inventor of the present invention discloses a covered wheel in which a tire is directly mounted on a rim. This type of tire is a cover wheel equipped with a hollow tire, including a plurality of elastic ring elements, raised from both sides of the rim to the middle, and spaced apart from each other in the circumferential direction, and each ring element is in the direction close to the tire Gradually thins.

When a relatively small impact or load is applied to such a covered wheel, the elastic ring elements deform in their thinner parts, that is, near the ridge of the rim, to cushion the impact, while the larger Shocks or loads are cushioned by deformation of the thicker section near the bottom of the rim.

However, since the covered tire absorbs the impact entirely by the elastic deformation of the elastic ring-shaped element, it is difficult to select a material for the elastic element used under relatively large load conditions. Such tires can be filled with compressed air if desired, however in this case the tire must be repaired when a flat or puncture occurs.

The object of the present invention is to provide an airtight solid tire with higher elasticity compared with hollow tires with sufficient load-carrying capacity, especially to provide a solid tire which can be used even when the vehicle is running empty It will also fully cushion the impact from the road surface, thereby preventing driver fatigue.

In order to achieve the above object, the present invention provides a solid tire core, which includes a ring-shaped elastic element, the inner surface of the tire is mounted on the outer surface of the ring-shaped elastic element, and the outer surface of the rim is mounted on the inner surface. The annular elastic member includes a cavity portion extending along the circumference of the core, and the cavity portion is positioned and shaped to enhance the elasticity of the core.

According to the above construction, this tire is composed of two separate parts, namely the tire core and the casing. Thus, the tire core only has to function as an elastic element, while the casing, on the other hand, only has to function as a ground-engaging element in contact with the road surface. Therefore, it becomes possible to freely select the material, shape, etc. of the tire core only in accordance with its function as the elastic member. In other words, the shape of the tire core and the like can be easily selected from a wide range, and various shapes of cavity portions as described below can be employed. Therefore, it is possible to provide a tire having as high an elasticity as a hollow tire without affecting the load-carrying capacity, and especially to provide a solid tire which sufficiently cushions the load from the road even when the vehicle is running empty. impact, thereby preventing driver fatigue. Moreover, when the surface of the tire contacting the ground wears so that the groove of the tire becomes shallow, only a new tire needs to be replaced, and the tire core can be reused. Therefore, the solid tire of the present invention is more economical than conventional integrally formed solid tires.

Preferably, the cavity portion is an annular groove formed along the ridge of the core, wherein the annular groove widens toward the rim in the direction of the tire axis. Due to this structure, when a load is applied to the ridge of the tire core, since the bottom of the cavity portion inside the groove expands toward the tire axis, the portion across both sides of the groove is elastically deformed as if bent toward the deepest part of the groove .

In this case, when a small load is applied, the opposite surfaces of the groove are close together or in contact with each other, that is, the load is carried by the deformation of the portion straddling the sides of the groove. When a large load is applied to the ridge portion of the tire core, the tire core elastically deforms toward the deeper portion of the annular groove, so that the tire core is squeezed and deformed corresponding to the deformation of the tire.

Therefore, the tire core of the above-mentioned structure bears a small load such as a short-term impact by the elastic deformation across the two sides of the tire core groove, and withstands a large load applied for a long time by the bending and extrusion deformation inside the tire. load.

Preferably, the annular groove engages a boss formed on the inner surface of the carcass. Due to this structure, the boss on the inner surface of the tire engages with the annular groove of the tire core, which reliably prevents the tire from sliding along the axis of the tire.

Preferably, the cavity portion is a slit extending in the circumferential direction in the outer surface of the core. Due to this structure, when a small load is applied to the tire core, as the tire core deforms, the opposite surfaces of the slit separate from each other (i.e. form a hollow portion), in this way, the slit helps the tire core to generate deflection. Sexual or elastic deformation to bear the load. When a large load is applied, the part deeper than the slit is squeezed and deformed to fully bear the load. If the tire core includes only one slit, it tends to deform symmetrically. In this case, it is preferable to form the slit in the ridge of the core.

Preferably, said tire core includes a plurality of slots extending longitudinally on the outer surface of the core. Due to this structure, multiple slits can generate flexibility and elastic deformation, thereby more effectively cushioning impact.

Preferably, the cavity portion is a hollow portion so that the tire core is thinner at the rim side and at the outer sidewall than at other portions. Due to this structure, when a small load is applied, the thinner portion of the tire core, that is, the portion on the rim side or the sidewall can be elastically deformed to bear the load. When a large load is applied, the entire tire core is crushed and deformed inside the tire.

As mentioned above, any tire core with the above-mentioned structure can bear a small load with a relatively low elastic force, and can bear a relatively large load with a corresponding elastic force. That is to say, the tire core can show its best cushioning effect under various conditions.

Preferably, the solid tire also includes a filler to fill the cavity portion.

Furthermore, it is preferable that the tire core can be disassembled into a plurality of parts along the tire axis direction. Due to this structure, the production time is shortened and the production process is simplified. Also, assembly operations can be efficiently performed.

Preferably, in order to increase the strength of the internal parts of the core, a wire mesh is embedded in the tire core. Due to this structure, the tire core has higher strength and thus can withstand greater loads. Even if a large load is applied for a long time, it can prevent plastic deformation and permanent deformation.

Preferably, the tire core also includes circumferentially spaced grooves or bosses in or on its outer surface for securing the tire casing to the outer surface of the core. Due to this structure, wear between the outer surface of the tire core and the inner surface of the tire casing can be avoided, and frictional heat generated therebetween can also be avoided.

The solid tire core also includes circumferentially spaced grooves or bosses in or on its inner surface for securing the wheel to the inner surface of the core. Due to this structure, even after a long period of use, the wheel is firmly engaged with the tire core so that the tire core does not spin relative to the wheel. Thus, driving force can be reliably transmitted from the wheel to the tire core. Also, when the wheel stops moving, so does the tire core, allowing the vehicle's brakes to work reliably.

Preferably, the solid tire core includes a plurality of grooves formed in the outer surface of the core to enhance the resiliency of the outer part of the core. Due to this structure, the boss between the grooves is in contact with the inner surface of the tire, thereby improving the friction between the tire core and the tire and preventing the tire from sliding relative to the tire core. This prevents the outer surface of the tire core from being worn by the inner surface of the tire casing, and also avoids the generation of frictional heat between the two.

Preferably, the plurality of grooves are arranged along the axis of the tire. Due to this structure, the frictional force between the tire core and the tire casing in the rotation direction can be increased, thereby preventing the tire casing from sliding relative to the tire core in the rotation direction.

Preferably, the plurality of grooves are arranged circumferentially. Due to this structure, the frictional force in the axial direction between the tire core and the tire casing can be increased, thereby preventing the casing from sliding in the axial direction with respect to the tire core.

Preferably, the above-mentioned plurality of grooves become wider near the outer surface of the tire core. Due to this structure, when a load is applied to the tire core, the protruding portions straddling both sides of the groove are elastically deformed, such as buckled. Thus, when a small load is applied, the opposite inner walls of the groove approach or touch each other. That is, the parts spanning both sides of the groove are elastically bent to bear the load. When a large load is applied to the ridge portion of the tire core, the tire core is elastically deformed toward the deeper portion of the groove, so that the tire core is compressed and deformed corresponding to the deformation of the tire.

Therefore, corresponding to the above-mentioned structure of the tire core, the parts across both sides of the groove are elastically bent to withstand a small load, such as a short-term impact; the entire tire core is bent and squeezed inside the tire, thereby cushioning and Withstands heavy loads applied for long periods of time.

Preferably, the carcass of the solid tire of the present invention has an inner surface mountable to the outer surface of any of the solid tire cores described above. Due to this structure, when the surface of the tire contacting the ground wears down so that the grooves of the tire become shallow, only a new tire needs to be replaced, and the tire core can be reused. Therefore, the solid tire of the present invention is more economical than conventional integrally formed solid tires.

Preferably, the casing of the solid tire of the present invention includes grooves or bosses formed on or in its inner surface for engagement with corresponding bosses or grooves formed on or in the solid tire core, It is used to fix the solid tire core. The solid tire core has circumferentially spaced grooves or bosses formed on its outer surface to fix the tire. Due to this structure, the tire casing can be prevented from sliding relative to the tire core, thereby avoiding wear between the outer surface of the tire core and the inner surface of the tire casing, and also avoiding the generation of frictional heat therebetween.

The solid tire wheel of the present invention includes retaining elements circumferentially spaced on its outer surface for securing the solid tire core. Thanks to this construction, even after prolonged use, the wheel and the tire core can be securely interlocked by means of the stop element, so that the tire core cannot spin freely relative to the wheel. Thus, driving force can be reliably transmitted from the wheel to the tire core. Moreover, when the wheel stops moving, the tire core also stops moving, so that the braking mechanism of the vehicle works reliably.

Preferably, the above-mentioned stop element is a groove or a boss formed in or on the outer surface of the wheel for fixing the tire core; the tire core has corresponding circumferentially spaced bosses or grooves for Secure the wheel to the inner surface of the core. Due to this structure, the grooves or bosses formed in or on the tire core are stably and reliably engaged with the corresponding grooves or bosses formed in or on the wheel, thereby more reliably preventing the tire core from facing each other. slip on the wheels. Accordingly, driving force can be more reliably transmitted from the wheel to the tire core even after a long period of use. Also, when the wheel stops moving, the tire core also stops completely, allowing the vehicle's braking mechanism to work reliably.

Preferably, the above-mentioned stop element is a knife-shaped disc element radially protruding from the wheel. Due to this structure, when the tire core is fixed on the wheel, the edge of the stop element, that is, the disk element, due to its blade shape, cuts into the inner surface of the tire core, allowing the wheel to fully engage with the tire core, thereby making it more reliable. This prevents the tire core from slipping relative to the wheel without having to provide special stop elements on the tire core. Therefore, driving force can be more reliably transmitted from the wheel to any tire core without special engaging elements. When the wheel stops moving, the tire core also stops completely, allowing the vehicle's braking mechanism to work reliably.

Another solid tire of the present invention is a solid tire integrally formed by a tire casing and an annular rubber element having an inner diameter suitable for being mounted on a wheel rim. There is a hollow portion in the annular rubber member, and therefore, the portion on the rim side and the sidewall of the annular rubber member is thinner than other portions.

Due to the above structure, when a small load is applied, the thinner part of the annular rubber element, that is, the part on the rim side or the outer tire side, can be elastically deformed to bear the load; when a larger load is applied, the entire annular rubber The elements are extruded in the tire. Therefore, the tire core can bear a smaller load with a lower spring force and a larger load with a corresponding spring force. That is to say, the tire core can show its best cushioning effect under various conditions.

Preferably, in order to increase the strength of the inner part of the annular rubber element, a wire mesh is embedded in the annular rubber element. Due to this structure, the annular rubber element has a higher strength and thus can withstand greater loads. Even if a large load is applied for a long time, it can prevent plastic deformation and permanent deformation.

Preferably, the solid tire further includes circumferentially spaced grooves or bosses in or on the inner surface of the annular rubber member for securing the wheel. Due to this structure, the annular rubber member can be prevented from slipping relative to the wheel, whereby the wheel can be prevented from being worn by the inner surface of the annular rubber member, and frictional heat can also be prevented from being generated therebetween.

In addition, solid tire production methods include:

In a first step, preparing the part as a tire core, i) a base part corresponding to the inner part of the tire core and ii) first and second elastic halves, obtained by dividing their outer part along a plane passing through the axis of rotation of the tire;

In a second step, placing the first elastic half-body and the base part in a first mold having a shape corresponding to the half-body formed by separating the tire core along a separation plane passing through the axis of rotation of the tire;

In the third step, an intermediate mold having a shape corresponding to the cavity part is positioned in the first mold, the intermediate mold includes a plurality of individual molds cut along the radial direction of the solid tire;

The fourth step is to put the second elastic half body on the first elastic half body;

In the fifth step, the second mold is positioned in the first mold and the intermediate mold on which the first and second elastic half bodies and the base part have been placed, the second mold has a shape corresponding to the remaining half body of the tire core;

The sixth step is to vulcanize the first and second elastic half bodies and the base part placed in the first and second molds and the intermediate mold;

The seventh step is to take out the vulcanized tire core from the first mold, the second mold and the intermediate mold.

Through the above-mentioned production method, after the contact surfaces of the elastic half body and the base part are bonded to each other, the intermediate mold can be disassembled separately as a plurality of independent molds, whereby it is possible to easily produce tire core. Also, since the intermediate mold is inserted into the central portion of the tire core, the inside of the tire core can be directly heated by the intermediate mold in the vulcanization process step. Accordingly, the entire tire core can be heated in a shorter time, whereby the vulcanization treatment time is shortened, thereby shortening the overall production time.

Preferably, each of the plurality of individual molds includes engagement elements for engaging adjacent individual molds. Due to this structure, the independent molds are joined to each other at the joining portion, so even if the second mold is squeezed in the vulcanization process step to press the intermediate mold, the intermediate mold will not be deformed, and high-precision rings can still be produced. Grooves or slits.

Preferably, the plurality of independent molds includes three independent molds obtained by radially and equally dividing the intermediate mold into three parts. Due to this structure, each individual mold has the same shape and can be used as the same individual mold. Also, as viewed from the center of the intermediate mold, the adjacent connection portions between the individual molds exist only in one direction, thereby giving the intermediate mold a higher strength. As a result, the intermediate mold is less prone to deformation, enabling higher precision annular grooves or slits to be produced.

Preferably, each of the above-mentioned independent molds has a groove or a boss for fixing at least one of the first and second molds, and at least one of the first and second molds also includes a A groove or boss on which grooves or bosses engage. Thanks to this structure, it is possible to precisely place the intermediate mold relative to the first and second molds. Thus, a high-precision tire core can be produced.

Other methods of producing solid tire cores include:

The first step is to prepare the parts as the tire core, a base part corresponding to the inner part of the tire core and an elastic part corresponding to the outer part of the tire core;

In the second step, the base part is inserted and positioned between the first mold and the second mold along the tire axis direction, and when assembled together, the molds form a molding space corresponding to at least a part of the base part;

In a third step, placing the elastic part on the base part already placed in the first and second moulds;

In the fourth step, the third and fourth molds are positioned on the first and second molds on which the base part and elastic part have been placed. When the molds are assembled together, the third and fourth molds form an annular hollow portion corresponding to the outer portion of the tire core and can be separated by a plane extending along the axis of rotation of the tire;

The fifth step is to vulcanize the elastic part and the base part placed in the first to fourth molds;

The sixth step is to take out the vulcanized tire core from the first to fourth molds.

According to the above-mentioned production process, it is only necessary to use four molds, namely: the third and fourth molds, which have a shape corresponding to a half body of the tire core, in which grooves or slits are made, and the half body is formed by sectioning along the direction of the tire axis. Obtained by opening the tire core; first and second molds for positioning the base part. This makes it possible to easily produce tire cores with complex shapes, such as those with annular grooves or slits. Furthermore, since the mold has a shape corresponding to a half body with annular grooves or slits obtained by sectioning along the tire axial direction, it becomes possible to produce grooves or slits with high precision. Also, since the parts having shapes corresponding to the annular grooves and slits of the third and fourth molds are inserted into the center portion of the tire core, the inside of the tire core can be directly heated in the vulcanization treatment step. Accordingly, the entire tire core can be heated in a shorter time, whereby the vulcanization treatment time is shortened, thereby shortening the overall production time.

Fig. 1 is a sectional view of the first embodiment;

Fig. 2 (a) is a partial cutaway side view of the tire core in the first embodiment;

Fig. 2 (b) is a sectional view of the tire core along line II-II in the first embodiment;

Fig. 3 (a) is a partial sectional side view of the tire cover in the first embodiment;

Fig. 3 (b) is the sectional view of cover tire along III-III line in the first embodiment;

Fig. 4 is a sectional view of the second embodiment;

Fig. 5 is a sectional view of the third embodiment;

Fig. 6 is a partial sectional view of the fourth embodiment;

Fig. 7 is a partial sectional view of the fifth embodiment;

Fig. 8 is a partial sectional view of the sixth embodiment;

Fig. 9 is a partial sectional view of the seventh embodiment;

Fig. 10 is a partial sectional view of the eighth embodiment;

Fig. 11 is a sectional view of the ninth embodiment;

Fig. 12 (a) is a partial sectional side view of the tire core in the ninth embodiment;

Fig. 12(b) is a sectional view of the tire core along line IV-IV in the ninth embodiment;

Fig. 13 (a) is a partial sectional side view of the wheel in the ninth embodiment;

Fig. 13 (b) is the cross-sectional view along the V-V line of the wheel in the ninth embodiment;

Figure 14(a) is a partial cutaway side view of another wheel comprising a stop element;

Figure 14(b) is a sectional view of another wheel comprising a stop element along line VI-VI;

Fig. 15 is a sectional view of the tenth embodiment;

Fig. 16(a) is a partial cutaway side view of the tire core in the tenth embodiment;

Fig. 16(b) is a sectional view of the tire core along line VII-VII in the tenth embodiment;

Fig. 17 is a schematic sectional view illustrating a tire core production process;

Fig. 18 is a plan view illustrating the structure of the intermediate mold;

Fig. 19 (a) is a cross-sectional view showing the first shape of the connecting portion of the independent mould;

Fig. 19 (b) is a cross-sectional view showing a second shape of the connecting portion of the independent mould;

Fig. 19 (c) is a cross-sectional view showing a third shape of the connecting portion of the independent mould;

FIG. 20( a) is a sectional view showing a first example of a cross-section of an independent mold constituting an intermediate mold;

FIG. 20( b) is a cross-sectional view showing a second example of the cross-section of the independent molds constituting the intermediate mold;

FIG. 20( c) is a sectional view showing a third example of the cross-section of the independent molds constituting the intermediate mold;

Figure 21(a) is a first sectional view for illustrating another production process, showing a tire core part;

Figure 21(b) is a second sectional view illustrating another production process, showing a tire core part;

Figure 21(c) is a third cross-sectional view illustrating another production process, showing a tire core part;

Fig. 22 is a schematic cross-sectional view further illustrating other production processes of the tire core.

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 to Fig. 3 have shown the first embodiment of the present invention, namely solid tire A, and its composition is: with rubber tire (hollow tire) namely cover tire 4, be wrapped on the annular elastic element and be tire core 3, tire core 3 Has an inner diameter suitable for mounting on the rim 2 of the wheel 1 . The tire core 3 has an annular groove 5 extending circumferentially along the ridge of the tire core. The annular groove 5 widens near the rim, like a fan. The wheel 1 in Fig. 1 is only shown as one part, for ease of explanation, it comprises a detachable annular part (a spring-like part with gaps), like a usual wheel, for fixing the tire core 3 on the on the flange portion of the wheel. When assembling, the tire core 3 is mounted on the wheel 1 together with the dismantled annular part, and then the annular part is put into the annular groove for fixing the tire core 3 on the wheel 1 . The embodiments described below (including those with detachable wheels) all have similar structures.

According to the needs of use, the tire core 3 is made of a material with a suitable bending coefficient and a suitable elastic extrusion deformation capacity, and there is no special limitation on the material. For example, urethane rubber or the like is the best material to achieve this modulus of flex and elastic extrusion deformation after proper selection of curing and/or blowing agents to be added. In the following embodiments, the elastic materials mentioned above can also be used.

The depth of the annular groove 5 is not limited to the illustrated example, that is, the bottom of the groove 5 can be located at a position closer to the rim 2 than the distance from the tire casing 4, or can be located at the same distance from the rim 2. Than the position of the cover tire 4 closer to the tire. By changing the depth of the groove 5 as described above, the bending strength and deformability of the tire core 3 can be adjusted according to the usage requirements of the solid tire.

As shown in Figures 1 and 3, according to the first embodiment, there is a rib 6 on the inner surface of the tire casing 4, which is accommodated by the annular groove of the tire core 3, thereby reliably preventing the tire core 3 from moving along the tire axis. The direction shifts.

As shown in Figures 1 and 2, there are four elongated grooves 7 extending along the tire axis in the outer surface of the tire core 3, and are circumferentially distributed at an angle of 90° from each other. And, as shown in Figure 1 and Figure 3, four ribs 8 are arranged on the inner surface of cover tire 4, and its position and shape are suitable for packing in the groove 7.

Due to this structure, the tire casing 4 can be prevented from sliding relative to the tire core 3 rotating with the rim 2, thereby avoiding friction and frictional heat generated therebetween. The number, position and shape of the stoppers, i.e. the grooves 7 and ribs 8, are not limited to the above, as long as the tire casing 4 can be prevented from sliding relative to the tire core 3, other numbers, positions and shapes of stops can also be used. element.

The solid tire A is formed by wrapping a tire core 3 with a cover tire 4 . Therefore, when cover tire 4 wears and tear, only need change a new cover tire 4. In this respect, the solid tire of the invention is more economical to use than conventional integrally formed solid tires. Since the side portions of the tire casing 4 only enclose about half of each side of the tire core 3, the tire casing 4 can be mounted on or removed from the tire core 3 relatively easily.

When a load is applied to the ridge portion of the tire core 3 of the solid tire of the above-mentioned structure in the first embodiment, as shown by the dotted line in the lower part of FIG. inside and thus close to each other. When a larger load is applied to the tire core 3, the tire core 3 elastically bends to the deeper part of the annular groove 5, and is extruded and deformed on the cover tire 4.

Correspondingly, the solid tire with the above structure can achieve the best cushioning effect in various situations, that is to say, the solid tire can bear a small load with low stiffness and a larger load with high stiffness. More specifically, solid tires not only have the advantage of bearing larger loads, but also can attenuate small vibrations caused by road surface undulations during vehicle driving, so that such vibrations will not be transmitted to the vehicle body.

If the solid tire of the above structure is subjected to such a large load for a long time, the tire core 3 will be deformed at a deformation rate of 10-20% or more, and the tire core 3 may thus be plastically (permanently) deformed. However, under normal load conditions, tires rarely deform at such a deformation rate. Moreover, in fact, the vehicle will not be allowed to bear such a large load for many days. A solid annular spring 3a (as shown in FIG. 1 ) with an arc-shaped cross section made of steel or other materials can be embedded in the tire core 3 to improve the elastic deformation strength of the tire core 3 . In this case, even if a load acts on the tire core 3 for a long time and causes plastic deformation of the rubber portion of the tire core 3, the spring 3a made of a metal material such as steel hardly undergoes plastic deformation, so that the tire core 3 There is also no permanent deformation. Therefore, even after a long period of use, the entire solid tire will not undergo permanent deformation and can maintain its original elastic properties, thereby improving the reliability of the solid tire.

Moreover, according to the above-mentioned embodiment, the tire core 3 is provided with the annular groove 5, and suitable elasticity can be obtained. However, it is also possible to put a filler into the groove 5 after the annular groove 5 has been produced. Soft materials such as foam rubber and sponge rubber can be used as fillers, so as not to weaken the elasticity of the tire core 3 . In this case, since the groove 5 is full of fillers, foreign matters such as earth and sand will not enter the groove 5 . As a result, the tire can be prevented from being out of balance when the vehicle is running, and the tire core will not be damaged by foreign matter, thereby improving the reliability of the solid tire. Since the filler and the tire core 3 are bonded to each other, there will not be too much pressure acting on the edge of the annular groove 5 of the tire core 3, thereby avoiding the occurrence of crack. This effect is particularly noticeable for the tire core 14 with the slits 15 described below. In this case, the annular hollow portion 16 may be omitted. The above fillers can also be used in the solid tires B-J described below to achieve the same effect.

Fig. 4 shows the second embodiment of the present invention, that is, a solid tire B, on the basis of the structure of the first embodiment, a wire mesh 9 embedded in the tire core 3 and extending circumferentially therein is added. The wire mesh 9 is preferably implanted on the side close to the rim 2, extends around the inner end of the groove 5, and is formed by stacking several layers of wire mesh. As the wire mesh 9, a conventional wire mesh generally used for a steel mesh radial tire can be used. Due to this structure, the portion of the tire core 3 close to the rim 2 is reinforced, so that the solid tire B can bear a large load. Also, even if a load is applied to the tire core 3 for a long time, the wire mesh 9 made of a metal material such as steel hardly undergoes plastic deformation. Therefore, even after a long period of use, the tire core 3 hardly undergoes permanent deformation and can maintain its original elastic properties, thereby improving the reliability of the solid tire.

As shown in Figure 5, the solid tire C in the third embodiment, on the structural basis of the first embodiment, has increased tire core 10, and tire core 10 has two core parts 10a and 10b, is extended along tire radial direction Each part has a wire mesh 9 implanted therein.

By using a tire core 10 comprising two or more parts separated along a tire radial plane, it is possible to reduce the vulcanization process time of the core parts 10a and 10b, thereby reducing the overall production time. Also, the core parts 10a and 10b each having the annular groove 5 can be easily taken out of the mold. This simplifies the production of the core parts 10a and 10b. Also, the tire core 10 can be easily loaded into the tire casing 4, thereby improving the assembling operation. In order to assemble multiple parts on the tire core 10, two discs are first put together to make a wheel 11, on which the parts 10a and 10b are installed on the rim 12, and then tightened with bolts and nuts inserted into the bolt holes 13 they. It is also possible to combine the core parts 10a and 10b by a common method such as bonding.

The wire mesh 9 of the solid tire C is implanted circumferentially into each part of the tire core 10, and the wire mesh 9 in the tire core 10 is dense near the rim 12 to provide good mechanical strength against deformation. Also, the wire mesh density of the tire core C gradually becomes higher in a direction approaching the rim of the tire core 10 . Therefore, it is possible to increase the strength of only the rim side portion of the tire core 10 without greatly changing the elastic characteristics of the tire core 10 outer side portion.

Figure 6 shows a fourth embodiment, a solid tire D, consisting of a casing 4 (hollow tire) surrounding a tire core 14 having a slit 15 extending circumferentially along its ridge in the outer surface of the core. In the following description, the same elements as those in the third embodiment are denoted by the same reference numerals, and thus their descriptions will not be repeated.

The slit 15 is about 1-10 mm wide, but can also be just a notch, for example cut with a knife. It is preferable to form a hollow portion 16 of circular cross-section at the deepest part of the slit 15 to avoid cracks.

When a relatively small load is applied to the tire casing 4, as shown by the dot-dash line in FIG. 6, the outer portion of the tire is deformed, and the slit 15 helps the tire core 14 to deform slightly and elastically. This is because the opposing surfaces of the slit 15 are separated from each other as the carcass 4 and tire core 14 are deformed, thereby forming a hollow portion therebetween. When a larger load is applied to the outer tire 4, the slit 15 and the entire tire core 14 are deformed to bear the larger load.

Fig. 7 has shown the fifth embodiment, namely solid tire E, is made up of casing 4 wrapping tire core 18, and there is an annular hollow part 19 in tire core 18, and its cross-section is circular and extends circumferentially, so that tire core 18 The remaining rim side portion is thinner than the tire side portion.

The solid tire E has special properties due to the special shape of the tire core 18 with the aforementioned hollow portion 19 . When a momentary small load such as an impact is applied, the thinner portion of the tire core 18, that is, the rim side portion, is elastically deformed to cushion the impact. When a large load is applied for a long time, the entire tire core 18, including the thicker part of the outer sidewall, is squeezed and deformed to bear the load. The cross-section of the hollow portion 19 is not limited to the circular shape shown in FIG. 7 , but may also be in other shapes, such as elliptical or fan-shaped.

In order to improve the load-bearing capacity of the tire core 18, a solid ring spring 3a (as shown in FIG. 1 ) or a metal wire made of metal (such as steel) used in the above-mentioned first embodiment can be implanted in the tire core 18. net. To achieve the same purpose, the tire core 18 may be made by mixing metal springs of common shapes, fiberglass, cloth, carbon fiber, fiber-reinforced resin, and the like. The helical or arcuate single strand indicated by reference number 18a in Figure 7 is obtained by unwinding a steel cord or special steel. The appropriate choice of wire thickness and length depends on the desired load carrying capacity of the solid tyre. For example, a helical or arcuate wire with a circumference of 1-2 cm may be used.

The helical or arcuate wire is used because, compared to a straight wire, it can deform with the deformation of the elastic rubber from which the tire core is made. More specifically, when the elastic rubber is deformed, the straight metal wire cannot be deformed with the deformation of the elastic rubber to be separated from it. On the other hand, due to the toughness of the helical or arcuate metal wire, it can be deformed with the deformation of the elastic rubber, thereby avoiding its separation.

By using this reinforcing element, it is possible to prevent permanent deformation of the tire core 18 due to the application of high loads, thereby increasing the load-bearing capacity of the core and increasing the toughness of the resulting tire. Moreover, even when a load is applied to the tire core 18 for a long time and causes plastic deformation of the rubber portion of the tire core 18, the metal wire 18a made of metal such as steel hardly undergoes plastic deformation, so that the tire core 18 does not undergo permanent deformation. out of shape. Therefore, even after a long period of use, the solid tire can still maintain its original shape and elastic characteristics, thereby improving the reliability of the solid tire. The reinforcing treatment described above is also applicable to any embodiment of the present invention that includes a tire core or annular rubber element.

In the process of producing a tire core containing the aforementioned hollow portion, the tire core 18 may comprise two parts separated by a bisecting plane extending radially of the tire, as in the third embodiment, the solid tire C shown in FIG. . In this case, the vulcanization treatment time of the tire core 18 can be shortened, and thus the overall overall production time can be shortened. Also, the mold for making the hollow portion 19 can be easily taken out, so that the hollow portion can be easily made to produce the tire 18 with ease.

FIG. 8 shows a sixth embodiment of the invention, namely a solid tire F, consisting of a tire casing 17 integrally molded on an annular rubber element 20 . The annular rubber member 20 has a hollow portion 21 with an approximately fan-shaped cross section. Thus, the outer sidewall portion of the element 20 is thinner than the rim side portion. A hollow portion 21 is arranged in the element 20 and extends circumferentially therein.

FIG. 9 shows a seventh embodiment of the present invention, that is, a solid tire G consisting of a tire casing 17 integrally molded on the outer surface of an annular rubber element 23 . The annular rubber member 23 has an annular hollow portion 24 having a circular cross section. Therefore, the remaining tire side portion of the annular rubber member 23 is thinner than the rim side portion. An annular hollow portion 24 is arranged in the element 23 and extends circumferentially therein.

According to the embodiment shown in Fig. 8 and Fig. 9, the following benefits can be obtained. When a small load such as an impact is applied to the solid tire F or G, the thinner portion of the annular rubber member 20 or 23, that is, the sidewall portion, is elastically deformed to bear the load. When a large load is applied, the entire rubber member 20 or 23, including the thicker portion on the rim side, is elastically deformed to bear the load. The cross-section of the hollow portion 21 or 24 is not limited to the fan-shaped or circular shape shown in FIG. 8 and FIG. 9 , but may be other shapes, such as an ellipse. Moreover, there is a parting line 22 in the sixth or seventh embodiment, which extends from the deepest part of the approximately fan-shaped or circular hollow portion 21 or 24 to the rim 12, so that the hollow portion 21 of approximately fan-shaped cross-section can be made using a mold. Or a hollow portion 24 with an approximately circular cross section, thereby simplifying the production process. Therefore, according to the sixth or seventh embodiment, since the number of parts is reduced, the production process is simplified, so that a low-cost solid tire can be provided.

FIG. 10 shows an eighth embodiment of the invention, a solid tire H, comprising a plurality of long slits 25 and short slits 26 formed in the outer surface of a tire core 27 on both sides of the annular groove 5 . In this case, when a load is applied to the ridge of the tire core 27, the rubber portions straddling both sides of the annular groove 5 elastically bend toward the inner cavity portion and approach each other. Also, the long slits 25 and the short slits 26 are also bent and elastically deformed toward the annular groove 5 following the deformation of the tire casing 4 and the tire core 27 . On the other hand, when a large load is applied to the ridge portion of the tire core 27, the tire core 27 is compressed and elastically deformed toward a deeper portion of the annular groove 5. As shown in FIG. Therefore, compared with the above-described embodiments, the tire core can bear a small load with low stiffness, thereby more effectively cushioning impact, and bear a large load with high stiffness. In other words, the tire core can perform the best cushioning effect in every situation.

The long slit 25 and the short slit 26 are usually about 1-10mm wide, but can also be just a gap. A hollow portion (not shown) of circular cross-section is preferably formed in the deepest portion of the slits 25 and 26 to avoid cracks. Moreover, the long slits 25 and the short slits 26 can not only be used together with the annular groove 5 in this embodiment, but can also be used alone if their shapes, numbers and positions are appropriately changed. In addition, these slits may be used in appropriate combination with the slit 16 shown in FIG. 6 or the hollow portion 19 shown in FIG. 7 or the like.

Fig. 11 to Fig. 13 have shown the ninth embodiment of the present invention, namely solid tire 1, and the first embodiment is similar, and it is wrapped on tire core 31 by cover tire 4 and constitutes, and tire core 31 is suitable for being installed on wheel 41 diameter on the rim. In the following description, the same elements as those in the first embodiment are denoted by the same reference numerals, and thus their descriptions will not be repeated.

As shown in Fig. 11 and Fig. 12, there are four elongated grooves 32 in the inner surface of the tire core 31, extending along the tire axis direction and circumferentially distributed at an angle of 90° from each other. Moreover, as shown in FIGS. 11 and 13 , as stopper elements, four bosses 42 are arranged on the outer surface of the rim of the wheel 41 , and its position and shape are suitable for fitting into the groove 32 .

In this case, the boss 42 on the wheel 41 is firmly engaged with the groove 32 on the tire core 31 even after a long period of use, so that the tire core 31 does not run idle relative to the wheel 41 . Thus, driving force can be reliably transmitted from the wheel 41 to the tire core 31 and the tire case 4 . Moreover, when the wheel 41 stops moving, the tire core 31 and the tire casing 4 also stop moving, so that the brake mechanism of the vehicle can work reliably. The number, position and shape of the fixing groove 32 and the boss 42 are not limited to the above, as long as the tire core 31 can be prevented from sliding relative to the wheel 41, other numbers, positions and shapes of fixing elements can also be used.

Next, another solid tire wheel with a stop element for fixing the tire core will be described. As shown in Figure 14, on the outer surface of the rim of the solid tire wheel 45, there are four knife-shaped disc elements 46, which protrude radially along the radial direction of the wheel 45, extend along the axial direction of the tire, and mutually Circumferentially distributed at an angle of 90°. As a tire core mounted on the wheel 45, a tire core 3 as shown in FIG. 1 or the like is used. In this case, the boss 32 shown in FIGS. 11 and 12 is no longer necessary. The casing used is a casing 4 or the like adapted to be mounted on a tire core 3 .

The height of the disc-like element 46 may be 5-20 mm, appropriately chosen according to the diameter of the tire or similar. Also, the edge of the disc member 46 is blade-like. When the tire core is mounted on the wheel 45, the edge portion of the disk member 46 cuts into the inner surface of the tire core made of elastic rubber. Thus, the disc-shaped member 46 on the wheel 45 is fully engaged with the tire core, thereby reliably preventing the tire core from slipping relative to the wheel 45 even after a long period of use. As a result of this structure, the drive force can be reliably transmitted from the wheel 45 to any of the aforementioned tire cores without special stop elements. When the movement of the wheel 45 stops, the movement of the tire core also stops completely, thereby allowing the vehicle's braking mechanism to work more reliably. The number, position and shape of the disk-shaped elements 46 as the stoppers are not limited to the above, as long as the tire core can be prevented from sliding relative to the wheel 45, other numbers, positions and shapes of stoppers can also be used.

Figures 15 and 16 show a tenth embodiment of the invention, a solid tire J, comprising a plurality of intersecting grooves 52, i.e. circumferentially extending grooves and axially extending recesses on the outer surface of a tire core 51. groove. These grooves 52 are distributed on both sides of the annular groove 5 . In the following description, the same elements as those in the first embodiment are denoted by the same reference numerals, and thus their descriptions will not be repeated.

In this embodiment, the boss 53 between the grooves 52 is in contact with the inner surface of the tire 4 to increase the frictional force between the tire core 51 and the tire core 4, thereby preventing the tire cover 4 from sliding relative to the tire core 51. This avoids wear between the outer surface of the tire core 51 and the inner surface of the tire casing 4, and also avoids the generation of frictional heat between the two.

When a load is applied to the ridges of the tire core 51, the upper portions across both sides of the annular groove 5 bend toward the inner cavity portion and are further elastically deformed to approach each other. Then, the plurality of grooves 52 are also bent and elastically deformed toward the annular groove 5 following the deformation of the tire casing 4 and the tire core 51 . Next, when a large load is applied to the ridge of the tire core 51 , the tire core 51 is pressed and elastically deformed toward a deeper portion of the annular groove 5 . Therefore, the tire core can withstand a small load with low stiffness, thereby more effectively cushioning shocks, and withstand a larger load with high stiffness. In other words, the tire core can perform the best cushioning effect in every situation.

The plurality of grooves 52 may be arranged only in the axial direction of the tire. In this case, the frictional force between the tire core 51 and the tire casing 4 in the tire rotation direction can be increased to more effectively prevent the tire casing 4 from sliding relative to the tire core 51 in the tire rotation direction. Furthermore, the plurality of grooves 52 may also be arranged only in the circumferential direction of the tire. In this case, the frictional force between the tire core 51 and the tire casing 4 in the direction of the tire axis can be increased to more effectively prevent the tire casing 4 from sliding relative to the tire core 51 in the direction of the tire axis.

Also, the plurality of grooves 52 preferably become wider toward the outside. In this case, when a load is applied to the tire core 51, the rubber portion straddling both sides of the annular groove 52 is easily elastically deformed and bent. Therefore, when a small load is applied, the inner walls of adjacent bosses 53 approach or contact each other. In other words, the bosses between the grooves are elastically deformed, thereby exhibiting a cushioning effect. In addition, when a large load is applied to the ridge portion of the tire core 51, the tire core 51 is elastically deformed toward a deeper portion of the annular groove 5, and at the same time, is compressed as the tire deforms. In this example, the groove 52 has a wedge-shaped cross-section, but it may also be other shapes, such as an inverted trapezoid. However, in the case of a wedge-shaped cross-section, it is preferable to form a hollow part (not shown) with a circular arc in cross-section at the deepest part of the groove 52 to avoid cracks. Moreover, the plurality of grooves 52 can not only be used together with the annular groove 5 in this embodiment, but can also be used alone if their shapes, numbers and positions are appropriately changed. In addition, it is also possible to use the groove 52 in appropriate combination with the slit 16 shown in FIG. 6 or the hollow portion 19 shown in FIG. 7 or the like.

Therefore, the above-mentioned solid tires A-J exhibit a good cushioning effect, which is produced by the special shape of the corresponding tire core or annular rubber element. Each tire is capable of carrying a small load with a low stiffness and a larger load with a corresponding stiffness. In other words, each tire can show its best cushioning effect in various situations.

The maximum width of the groove 5, the slit 16 and the hollow part 19 in the above-mentioned solid tires A-E and H-J, that is, the maximum width in the direction along the tire axis, should be larger than the solid tire core 3, 10a, 14, 18, 27, 31 and 51 are 0%, but not more than 30%, preferably greater than 0%, and not more than 20% of the maximum width of the approximately circular cross-section taken along the axial direction of the solid tire A-E and H-J. And, the maximum depth of groove 5, slit 16 and hollow part 19 of above-mentioned solid tire A-E and H-J, namely the maximum length on the direction perpendicular to the axis of the tire (i.e. from the tire to the wheel direction), should be greater than the solid tire core 3 , 10a, 14, 18, 27, 31 and 51 are 15% of the maximum length of the approximately circular cross-section taken along the axial direction of solid tires A-E and H-J, but not more than 67% (1/3), preferably greater than 15 %, not exceeding 50%. Since the thickest portion bears the greatest load acting on the solid tire, the annular groove or the like is preferably formed at least in the axially thickest portion of the tire in a cross-section taken along the tire axis. In this case, portions located on both sides of the groove, slit, or hollow portion, on a cross-section taken in the direction of the tire rotation axis. An approximate triangle or sector is formed, in which the circle is divided into one of four equal parts. When a load is applied, the tire core first deforms at the highest point of the tire core outer sidewall, that is, the narrowest part of the tire core along the tire axis. and in turn toward the inside of the tire core. Therefore, the tire core can bear a small load with a low spring force and a large load with a high spring force. In other words, tires that provide optimum cushioning in every situation. The above also applies to the hollow portion 21 and the annular hollow portion 24 provided by the annular rubber members 20 and 23 in the solid tires F and G.

Also, the grooves 5 and slots 16 in the solid tires A-D and H-J are preferably made from the highest portion of the respective core outer sidewall portion. Due to this structure, the portions straddling both sides of the groove or slit can be deformed independently. For example, when a pebble or other similar things are rolled on one side of the tire, only the part on one side of the corresponding tire core is elastically deformed, thereby cushioning the impact.

In addition, a method of producing the above-mentioned solid tire core will be described below. Hereinafter, a method of producing a tire core 3 for a solid tire A will be described as an example. Fig. 17 is a schematic sectional view illustrating a method of producing a tire core. In the following description, for the convenience of illustration, the groove 7 and similar components are not mentioned, but can be made by adding corresponding shapes to the male and female molds described below.

As shown in FIG. 17, produced as parts of the tire core 3 are a base portion 58 corresponding to the inner portion of the tire core 3; elastic halves 56 and 57, separated along a line perpendicular to the axis of the tire, and the elastic halves Corresponds to the outer portion of the tire core 3 . These parts are produced from unvulcanized rubber according to the traditional production methods of solid tires. In this example, the reason for making the tire core 3 from separate parts, namely the elastic halves 56 and 57 and the base portion 58, is that in order to securely mount it to the rim of the wheel, the A bead filler made of steel wire or similar material is inserted to make it more rigid; while the elastic halves 56 and 57 must maintain the above-mentioned elastic properties. In other words, there is a difference in the elasticity of the base part and the elastic half. The reason for separating the elastic halves 56 and 57 along a line orthogonal to the tire axis is to facilitate the manufacture of the annular groove 5 . The number of discrete elements for the tire core is not limited to the above, and may be two or other numbers.

Then, a male mold 51 is prepared in a shape corresponding to one half piece obtained by cutting the tire core 3 along a separation line perpendicular to the tire axis. The elastic half body 56 and the base part 58 are put into the male mold 51 . Then, an intermediate mold 53 having a shape corresponding to the annular groove 5 of the tire core 3 is positioned in the male mold 51 .

The intermediate mold 53 will now be described in detail. FIG. 18 is a plan view for explaining the structure of the intermediate mold 53 . As shown in FIG. 18, the intermediate mold 53 includes three independent molds 53a-53c obtained by equally dividing the intermediate mold 53 at angular intervals of 120° along the tire radial direction. Accordingly, each individual mold 53a-53c has the same shape, allowing three equivalent molds to be used as individual molds 53a-53c. The middle mold 53 is not only of the three-part type as described above, but also can be of other number of split types. Also, the intermediate mold does not have to be equally divided.

Suitable materials for the individual molds 53a-53c are metals such as aluminum, copper and iron. Aluminum has good thermal conductivity and is therefore recommended to reduce the time required for the vulcanization step described below. Also, conduits 62a-62c are implanted along the edges of the respective individual molds 53a-53c through which fluid flows for heating during the vulcanization step. Water with an increased boiling point, such as sulfurized water, is injected into the pipes 62a-62c after being heated to a temperature suitable for the vulcanization treatment step, so that the inside of the tire core 3 can be heated to the temperature required for the vulcanization treatment step in a short time. required temperature. Thus, by using the pipes 62a-62c, the vulcanization treatment time can be further shortened. However, if the individual molds 53a-53c are made hollow, their structural strength will decrease. Accordingly, the ducts 62a-62c are preferably arranged slightly into the outermost portions of the individual molds 53a-53c.

The individual molds 53a-53c are respectively provided with grooves, that is, positioning holes 61a-61c. On the other hand, the male die 51 has three bosses 54 (see FIG. 17 ) for engaging with the positioning holes 61 a - 61 c to position the individual dies 53 a - 53 c relative to the male die 51 . Therefore, through the positioning holes 61a-61c and the groove 54, the individual molds 53a-53c can be precisely positioned relative to the male mold 51, thereby making a high-precision annular groove 5 in the tire core 3. Conversely, as long as the individual molds 53a-53c can be precisely positioned relative to the male mold 51, it is also possible to make grooves in the male mold 51 and bosses on the individual molds 53a-53c. The number, position and shape of the positioning grooves and bosses are not particularly limited.

On the peripheries of the individual molds 53a-53c are formed projecting portions 63a-63c which extend radially beyond the outermost circumference of the male mold 51 (shown by dotted lines in FIG. 18). Therefore, even after all the molds are united, the individual molds 53a-53c can be easily handled due to the protruding portions 63a-63c, thereby simplifying the production process. Instead of using the positioning holes 61a-61c described above, the male die 51 and the female die 52 can also be positioned relative to the individual dies 53a-53c by the protruding portions 63a-63c. Also, the shape of the protruding portions 63a-63c may be appropriately changed according to the shape of the vulcanizer or other aspects.

Fig. 19 is a sectional view showing the shape of the connection portion between separate molds. As shown in FIG. 19(a), a triangular engaging groove 65a is formed at one end of the separate mold 53a, and a triangular boss 65b is formed at the opposite end of the separate mold 53b, and is correspondingly positioned and formed to engage with the groove 65a. Recesses or bosses similar to those described above are provided in or on the ends of the respective individual molds 53a-53c. The grooves and bosses engage with each other so that the three separate molds 53 a - 53 c are snapped together to form the ring-shaped intermediate mold 53 . Therefore, since the grooves and bosses of the three independent molds 53a-53c are closely engaged with each other to maintain the shape of the intermediate mold 53, even if the female mold 52 is pressed in the vulcanization process step below to press the intermediate mold 53, the intermediate mold 53 will not produce deformation. Also, since the individual molds 53a-53c are obtained by radially equally dividing the intermediate mold 53, there is no separation line extending through the intermediate mold 53 in the radial direction. Accordingly, the strength of the intermediate mold against the bending force acting thereon in the vertical direction increases. In this way, highly precise grooves 5 can be formed on the tire core 3 . Various shapes can be selected for engaging grooves and bosses, for example, they can be rectangular as shown in Figure 19 (b), or tapered as shown in Figure 19 (c), as long as the shape of the middle mold 53 can be maintained Can.

Referring to Fig. 17, after the intermediate mold 53 is positioned, the elastic half body 57 is placed. Then, the female mold 52 is positioned. Then, after placing the elastic halves 56 and 57 and the base part 58, the male mold 51, the female mold 52 and the intermediate mold 53 are positioned in a vulcanizing machine (not shown) and molded at a predetermined pressure and temperature. Therefore, the elastic halves 56 and 57 and the base portion 58 are bonded together at their contact surfaces to produce the complete shape of the tire core 3, and the elastic properties of the vulcanized elastic halves 56 and 57 are obtained. Adjustment, so that the tire core 3 having the above-mentioned elastic properties is completed.

After the vulcanization step is finished, the female mold 52 is removed from the male mold 51, and the resulting tire core 3 with the intermediate mold 53 therein is taken out from the lower mold 51. Finally, the three individual molds 53 a - 53 c are removed from the tire core 3 . Through the above production process, the tire core 3 with the annular groove 5 can be produced.

As described above, after the elastic halves 56 and 57 and the base portion 58 are bonded to each other on their contact surfaces, the intermediate mold 53 can be removed as three independent molds 53a-53c, respectively, and thus can be easily removed from the tire core. 3, the individual molds 53a-53c are removed, thereby producing the tire core 3 with the annular groove 5. Also, since the intermediate mold 53 is inserted into the central portion of the tire core 3, the inside of the tire core 3 can be directly heated by the intermediate mold 53 in the vulcanization process step. Accordingly, the entire tire core can be heated in a shorter time, whereby the vulcanization treatment time is shortened, thereby shortening the overall production time.

The production method of the tire core 3 with the annular groove 5 has been described above. A tire core 14 or the like with slits 15 can also be produced in the same way by suitably changing the cross-section of the intermediate mould. FIG. 20 is a sectional view showing various examples of individual mold cross sections of the intermediate mold 53. As shown in FIG. The cross-sections suitable for the intermediate mold 53 include the tapered shape shown in Figure 20 (a), the inverted tapered shape shown in Figure 20 (b), the rectangular shape shown in Figure 20 (c), etc. Choose the shape of the groove or slit you need.

Moreover, by appropriately changing the shape of each mold, it is possible to produce in the same manner as the above-mentioned production method: a tire core 18 with an annular hollow portion 19, an annular rubber element 20 with a hollow portion 21, an annular hollow The annular rubber element 23 of the portion 24, the tire core 27 with the annular groove 5, the long 25 and short 26 slits, etc.

Next, another method of producing the above-mentioned tire core will be described. Fig. 21 is a sectional view of a tire component illustrating another method of producing a tire core. The method for producing the tire core 3 of the solid tire A in the above-mentioned embodiment will be described below as an example.

First, as in the above-mentioned production process, a non-vulcanized base portion 58 is prepared as a part of the tire core 3, which is then mounted on the rotary shaft of the tire building machine. Then, the rotating shaft is rotated to roll up a piece of unvulcanized or partially vulcanized elastic rubber to be attached to the inner surface of the base portion 58 to form an elastic portion 70a corresponding to the outer portion of the tire core 3, As shown in Figure 21(a). Next, by continuously rotating the shaft, the elastic rubber sheet is further rolled up to form an elastic portion 70b composed of laminated elastic rubber sheets, as shown in Fig. 21(b). According to the shape of the elastic portion 70b, the annular groove here is widened so that the above-mentioned intermediate mold 53 can be easily inserted thereinto. Also, in order to mold the tire core into a final shape (as shown in FIG. 21(c)) in a vulcanization treatment step described later, the elastic portion 70c is also widened corresponding to the increase in the width of the annular groove.

In the next step, the tire core parts shown in FIG. 21(b) are put into the male mold 51, the female mold 52 and the middle mold 53, respectively, as in the above-mentioned production process. Then, it is molded by a vulcanization machine under predetermined pressure and temperature. Accordingly, the base portion 58 and the elastic portion 70b of the elastic rubber sheet are bonded to each other to form the shape of a tire core, thereby completing the tire core composed of the base portion 58 and the elastic portion 70c as shown in FIG. 21(c). Therefore, according to this method, using the above-mentioned elastic half bodies 56 and 57, the same effect as the above-mentioned method can also be achieved. Meanwhile, since the width of the annular groove is larger than that of the intermediate mold before the tire core is vulcanized, the intermediate mold can be inserted more easily.

Next, another method of producing the above-mentioned solid tire will be described. The method for producing a solid tire with slits will be described below as an example. Fig. 22 is a schematic sectional view illustrating a method of producing a tire core. In the following description, for convenience of illustration, grooves or the like for engaging the tire casing are not mentioned, but can be made by adding corresponding shapes in the third and fourth molds described below.

As shown in FIG. 22, as in the production process of the conventional solid tire core, a base portion 87 is prepared as a part of the tire core 3 first. The base portion 87 corresponds to the inner portion of the tire core 3 . Other parts of the tire core except the base part 87, that is, the elastic member 86 corresponding to the outer part of the tire core 3, can use molds almost identical to the first to fourth molds described below (the difference is that they are not compared with The part corresponding to the base part 87), and adopt the same method as the traditional solid tire core production process to make. In this example, the reason for using separate parts, namely the elastic element 86 and the base part 87, is that in order to make it firmly engaged with the rim of the wheel, it is necessary to insert a steel wire or similar material into the base part 87. bead filler to make it more rigid; and the elastic element 86 must exhibit the above-mentioned elastic characteristics. In other words, there is a difference in elasticity between them. The number of discrete elements for the tire core is not limited to the above, and may be three or other numbers.

Next, the base portion 87 is clamped, positioned and fixed between the first and second molds 81 and 82 in the tire axial direction. In this embodiment, both the first and second molds have the same composite cylindrical shape, but differ in diameter. Molds obtained by dividing the first and second molds 81 and 82 into two again in the axial direction of the tire may also be used as the first and second molds. Then, the elastic portion 86 is placed relative to the base portion 87 fixed by the first and second molds 81 and 82, by which the elastic portion 86 contacts a predetermined portion on the outer surface of the base portion 87.

Next, a third mold 83 and a fourth mold 84 are prepared, and when the molds are pieced together, an annular hollow portion corresponding to the outer portion of the tire core is formed. The molds 83 and 84 can be separated by a plane extending in the direction of the tire rotation axis (a dotted line in FIG. 22 indicates a separation line between the third mold 83 and the fourth mold 84 ). The third and fourth molds 83 and 84 are positioned relative to the first and second molds 81 and 82 of the base portion 87 and the elastic portion 86 already positioned therein. Since the third and fourth molds 83 and 84 are integrally equipped with semicircular-shaped intermediate mold parts 83a and 84a corresponding to the slits on the tire core, it is possible to prevent the intermediate mold parts 83a and 84a from moving relative to the third and fourth molds. 83 and 84 move or deform so that the slits can be positioned and made with high precision in the tire core.

Molds obtained by dividing the third and fourth molds 83 and 84 into two again in the axial direction of the tire can also be used as the third and fourth molds. The third and fourth molds may also be divided into more than two halves.

Suitable materials for the intermediate molds 83a and 84a are metals such as aluminum, copper and iron. Aluminum has good thermal conductivity and is therefore recommended to reduce the time required for the vulcanization step described below. Moreover, in the production process shown in FIGS. 17 and 18, pipes (not shown) are selectively implanted at the edges of the respective intermediate mold parts 83a and 84a, and fluids flow through them so as to be carried out in the vulcanization treatment step. heating.

Next, after the elastic portion 86 and the base portion 87 are placed as described above, the first to fourth molds 81-84 are positioned in a vulcanizer (not shown) and molded at a predetermined pressure and temperature. Therefore, the elastic portion 86 and the base portion 87 are bonded together at their contact surfaces to produce the complete shape of the tire core with slits, and the elastic properties of the elastic portion 86 are adjusted so as to have the above-mentioned elasticity The characteristic tire core is complete.

After the vulcanization step is completed, the third and fourth molds 83 and 84 are removed, and finally the first and second molds 81 and 82 are removed from the resulting tire core. Through the above production process, a tire core with slits can be produced. In this embodiment, the tire core has an approximately circular cross-section and the third and fourth molds 83 and 84 cover the elastic portion 86 from the outer portion to the inner edge and beyond the thickest part of the tire core. However, since the elastic portion 86 is elastic and easily deformed, the third and fourth molds 83 and 84 can be detached from the finally obtained tire core. In particular, after the vulcanization step is completed, since the elastic member 86 is in a high-temperature state and is soft, it can be easily taken out immediately.

As mentioned above, using only four molds, it is possible to easily produce tire cores with complex shapes, that is, tire cores with slits. Also, since the third and fourth molds 83 and 84 are provided with the intermediate mold parts 83a and 84a, it is possible to make the slit with high precision. Also, since the intermediate mold parts 83a and 84a have shapes corresponding to the slits of the third and fourth molds 83 and 84, and are inserted into the center portion of the tire core, it is possible to directly perform vulcanization on the inside of the tire core in the vulcanization treatment step. heating. Accordingly, the entire tire core can be heated in a shorter time, whereby the vulcanization treatment time is shortened, thereby shortening the overall production time. In this embodiment, the production method of the tire core with slits has been described. However, if the shape of the cross-section of the middle mold is changed, the same production process can also be used to produce the tire core 3 with the annular groove 5 or similar parts.

The present invention can be applied to any type of solid tires, such as press-fitted solid tires, cured mounted solid tires and pneumatic solid tires. It finds application not only in solid tires for fork-lift trucks, industrial tractors, various low-speed trailers, loaders or similar equipment, but also in vehicles that usually use pneumatic tires, such as wheelchairs.

Claims (21)

1. A solid tire core, characterized in that it includes an annular elastic element, the annular elastic element has an outer surface on which the inner surface of the tire is mounted and an inner surface on which the wheel rim is mounted, the annular The elastic member includes a cavity portion extending in the circumferential direction of the core, and the cavity portion is positioned and shaped to enhance the elasticity of the core. 2. A solid tire core according to claim 1, wherein the cavity portion is an annular groove formed along a ridge of the core; and wherein the annular groove becomes wider at a portion toward the rim in the tire axial direction. 3. 2. The solid tire core of claim 2, wherein the annular groove engages a boss formed on the inner surface of the tire casing. 4. A solid tire core according to claim 1, wherein the cavity portion is a slot extending longitudinally on the outer surface of the core 5. The solid tire core according to claim 1, wherein the cavity portion is a hollow portion so that each of the rim side and the outer sidewall portion of the tire core is thinner than the other portion. 6. The solid tire core according to claim 1, further comprising a filler filling the cavity portion. 7. A solid tire core according to claim 1, wherein the tire core can be split into a plurality of core parts in the direction of the tire axis. 8. The solid tire core according to claim 1, further comprising a wire mesh implanted therein to enhance rigidity of inner parts of the core. 9. The solid tire core according to claim 1, further comprising grooves or bosses distributed in or on the outer surface at intervals in the circumferential direction for fixing the tire casing to the outer surface of the core. 10. The solid tire core of claim 1 further comprising circumferentially spaced grooves or bosses in or on its inner surface for securing the wheel to the inner surface of the core. 11. The solid tire core according to claim 1, further comprising a plurality of grooves formed in the outer surface of the core for improving the elasticity of the outer part of the core. 12. 2. The solid tire core of claim 1, wherein the plurality of grooves widen near the outer surface of the tire core. 13. A solid tire casing characterized in that it includes an inner surface for mounting it to the outer surface of a solid tire core as defined in claim 1. 14. A solid tire casing, characterized in that it includes grooves or projections formed on or in its inner surface, corresponding to the projections formed on or in the solid tire core defined in claim 9 Engages with a land or groove to hold a solid tire core. 15. A solid tire wheel, characterized in that it includes retaining elements spaced circumferentially on its outer surface for securing a solid tire core as defined in claim 1 . 16. A solid tire integrally formed from a tire casing and an annular rubber element having an inner diameter suitable for mounting on a wheel rim, characterized in that there is a hollow in the annular rubber element, so that the Each of the portions of the rim side and the sidewall is thinner than the others. 17. The solid tire according to claim 16, characterized in that in order to increase the strength of the inner part of the annular rubber member, a wire mesh is embedded in the annular rubber member. 18. The solid tire according to claim 16, characterized in that it further comprises grooves or bosses distributed circumferentially at intervals in or on the inner surface of the annular rubber member for fixing the wheel. 19. A method of producing a solid tire core as defined in claim 1, characterized in that the method comprises: In the first step, preparing parts as tire cores, i) a base portion corresponding to the inner portion of the tire core and ii) first and second elastic halves, separated along a plane passing through the axis of rotation of the tire except for the base portion obtained from the external part; In a second step, placing the first elastic half body and the base part in a first mold having a shape corresponding to the half body formed by separating the tire core along a separation plane passing through the axis of rotation of the tire; In the third step, an intermediate mold having a shape corresponding to the cavity part is positioned in the first mold, the intermediate mold includes a plurality of individual molds cut along the radial direction of the solid tire; The fourth step is to put the second elastic half body on the first elastic half body; In the fifth step, the second mold is positioned in the first mold and the intermediate mold on which the first and second elastic half bodies and the base part have been placed, the second mold has a shape corresponding to the remaining half body of the tire core; The sixth step is to vulcanize the first and second elastic half bodies and the base part placed in the first and second molds and the intermediate mold; The seventh step is to take out the vulcanized tire core from the first mold, the second mold and the intermediate mold. 20. A method of producing a solid tire core according to claim 19, wherein the plurality of individual molds each include engaging elements for engaging adjacent individual molds. twenty one. A method of producing a solid tire core as claimed in claim 1, characterized in that the method comprises: The first step is to prepare the parts as tire core, a base part corresponding to the inner part of the tire core and an elastic part corresponding to the outer part except the tire core base part; In the second step, the base part is sandwiched between the first mold and the second mold along the tire axis direction, and when assembled together, the molds form a molding space corresponding to at least a part of the base part; In a third step, placing the elastic part on the base part already placed in the first and second moulds; The fourth step is to position the third and fourth molds on the first and second molds where the base part and the elastic part have been placed. When the molds are assembled together, the third and fourth molds form a shape corresponding to the outside of the tire core. part of the annular hollow part and may be divided by a plane extending along the axis of rotation of the tire; The fifth step is to vulcanize the elastic part and the base part placed in the first to fourth molds; The sixth step is to take out the vulcanized tire core from the mold.

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